The Hammer Museum, in partnership with Ari Bhöd — the American Foundation for Tibetan Cultural Preservation — is pleased to present The Mandala Project. This two-week program will feature the construction of a Tibetan sand mandala by a team of traditionally trained Lamas visiting Los Angeles from the Thubten Choeling Monastery in Pharping, Nepal. The mandala they create will be a sacred painting, following precise and ancient instructions passed down over thousands of years. Millions of grains of colored sand will be sprinkled carefully on a flat surface over an elaborate 10-day ceremony.

“Half Houses” by Chilean architect Alejandro Aravena, of the firm Elemental. It is one of eleven building projects that transform poor communities in “Small Scale, Big Change,” an exhibition at the Museum of Modern Art. Photographer: Cristobal Palma/Museum of Modern Art via Bloomberg

In one of Africa’s most remote places, a three-room school rises from a hot, dry plain. The metal roof arches over spidery steel rods and mud-brick walls. It’s stark, gorgeous, simple.

We are looking at hope in the tiny village of Gando, Burkina Faso, West Africa, one of the exhibits in “Small Scale, Big Change: New Architectures of Social Engagement” at Manhattan’s Museum of Modern Art.

After making good as an architect, the designer returned to build the school his poor village so desperately needed.

At another school in Rudrapur, Bangladesh, fabrics in vibrant blue, red and lavender flutter from the doorways and cover the ceiling. Inspired by local adobe traditions, Bavarian architect Anna Heringer used thick walls to deflect the searing sun. Local residents framed an upper level in lightweight bamboo poles lashed together.

The result is an environment in which any kid would be happy to learn.

On an August afternoon, a shiny sports-utility vehicle pulled into a parking lot of pick-up trucks outside the only school in Cotopaxi. The artist Christo Javacheff took a deep breath and walked into the school’s gymnasium. Someone had set up a microphone under the basketball hoop, and two armed sheriff’s officers stood watch nearby. All the folding chairs planted on the rubbery court were filled, some with people wearing T-shirts that read, “Say No To Christo.”

The artist had fretted about this moment for months. “It’s our lion’s den,” he told his staff.

Known professionally by his first name, Christo is famous for draping entire buildings, valleys and New York’s Central Park in colorful fabric. Now, at age 75, he’s trying to convince a swath of southern Colorado to let him temporarily suspend flat sections of silvery fabric over a 42-mile-long stretch of the area’s Arkansas River. For two weeks, people will be able to drive alongside this mirror-like ribbon or raft underneath it, he says. He has spent $7 million and 18 years working out the logistics of the project, “Over The River,” and he is campaigning hard for the permits to pull it off.

In early 1991, the construction of a federal office building in lower Manhattan was halted after an unexpected discovery. Underneath the ground, covered by a patina of concrete and steel, was the coffin of a colonial-era African. It was not alone. Construction work was halted, archaeologists called in, and it was soon established that the site was a major burial ground from the 17th and 18th centuries. As many as 15,000 to 20,000 black men, women and children were buried there, by the historians’ count, making this one of the most important archaeological finds in all America.

The significance was not lost on New York’s people or its authorities. Here was something that challenged the prevailing idea that there was no slavery in colonial New York, and it immediately took on symbolic importance for the city’s African–American community. In 1993, the site was designated a National Historic Landmark, the most important designation for a national monument, and a status it shares with the Statue of Liberty. And, in February, a visitor centre was opened there. Among the poignant displays is one depicting the dual funeral of an adult and child.

The African Burial Ground National Monument is both moving and fascinating because of what it reveals about forgotten lives. But it also says something about broader trends in memorialisation. We’ve stopped putting great men on pedestals and started commemorating their victims. In the process we are are losing a sense that human history involved leadership and struggle and, yes, sacrifice. In focusing purely on victimhood we are in danger of turning history into a random series of tragic events, instead of something that was purposeful and directed. Something made rather than just experienced.

Phone calls and visitors and, yes, dreams from around the world are pouring into the small offices of the Friends of the High Line on West 20th Street in Manhattan these days.

Detroit is thinking big about an abandoned train station. Jersey City and Philadelphia have defunct railroad beds, and Chicago has old train tracks that don’t look like much now, but maybe they too…

The High Line’s success as an elevated park, its improbable evolution from old trestle into glittering urban amenity, has motivated a whole host of public officials and city planners to consider or revisit efforts to convert relics from their own industrial pasts into potential economic engines.

Today marks the annual pilgrimage of 100,000 sun-seeking music fans to the Southern California desert for the three-day Coachella Music and Arts Festival. Sure Jay-Z’s playing. So are Thom Yorke, MGMT, DEVO, and Gorillaz–but there are also giant art and architectural installations created by a who’s who of Southern California architects. This year, Crimson Collective, an L.A.-based group of artists, architects, and designers constructed Ascension, a 45-foot tall crane with a 150-foot wingspan.

The magnolia tree on the north side of Rittenhouse Square looks as if it were plucked from a Dr. Seuss book. Its split trunk is wrapped in a whimsical sweater of pinks, blues, purples, and oranges.

The tree cozy is the work of Jessie Hemmons, 23, a graduate student in psychology at Chestnut Hill College and census worker – and a graffiti artist with a soft side.

Hemmons is part of a growing trend of rogue knitters who have taken their “yarnbombing” to the street to brighten the cityscape. She ties crocheted flowers to lampposts, wraps bike racks with rainbow-colored covers, and gave the Rocky statue a scarf.

Her motivation is simple.

“Times are tough,” Hemmons said. “People want to see something bright and pretty.”

Yesterday morning she put up her largest installation yet. Passersby stopped to watch and snap pictures as Hemmons began stitching about 15 feet of knitting – a 30-hour project – to a tree near 19th and Walnut Streets.

The yarnbombing trend made headlines this month when three women in West Cape May, known only by their tag name, Salty Knits, began putting up knitting under the cover of night in the borough’s Wilbraham Park and outside private businesses.

Renderings show how hundreds of New York taxis will become mobile public art next month when their rooftop ad boards display works by, from left, Shirin Neshat, Alex Katz and Yoko Ono. (Photo illustrations courtesy of Show Media and Art Production Fund)

Those moving advertisements atop taxis generally deliver not-so-subtle messages, like which airlines to fly or movies to see, who makes the sexiest blue jeans or the coolest sunglasses.

High art they most certainly are not.

But for the month of January, Show Media, a Las Vegas company that owns about half the cones adorning New York City’s taxis, has decided to give commerce a rest. Instead, roughly 500 cabs will display a different kind of message: artworks by Shirin Neshat, Alex Katz and Yoko Ono.

The Nelson-Atkins Museum of Art did a smart, simple thing for the Christmas season the other day — small but smart and good for art…the smaller idea was aimed at the media, which is always in search of good images. On Dec. 15 — enough time for planning — the PR department sent out an email with the subject line “Need Christmas Art?” and attaching a PDF listing of all the nativity scenes it holds in its collection for which it had high-res images: a dozen in all.